Direct electric current rare gas lamp



Feb. 15, 1938. A. LEDERER -DIRIHHII' ELECTRIC CURRENT RARE GAS LAMP Original Filed July 25, 19 31 INVENTOR A at cm Lederer KTToRNEY Patented Feb. 15, 1938 manor EIECTRIC cmmnnr mum GAS Anton Lederer, Vienna, Austria;

Catherine Danzer and General Conrad Banda, executors of said Anton Lederer, deceased, assignors to Ernest Anton Lederer, Glen Ridge, N. J.

Application July 1931, Serial i No. 553,112. gesriewed July 9, 1937. In Austria February 20,

6 Claims. (01. ire-122) luminous envelope is formed enclosing the hot.

electrode or electrodes. The luminous envelope consists of an intense light which may be termed a core light or aureole immediately adjacent-the electrode or electrodes, and of a feebler lighting outer zone or shell. In order to obtain this light effect the following two essential conditions must be observed in the construction of the lamp: (1)

The electrodes determining the electric field must be arranged in such a way that at the operation voltage of the lamp, a distribution of the electric field or current density is produced which is sufiicient for the excitation to luminescence of the gas in all directions around the hot electrode or electrodes. (2) The wall of the lamp bulb should be at such a distance from the hot electrode or .electrodes as not to be an obstacle to the pro- .duction and development of the light phenomenon.

The object of the present invention is to construct various forms of \these lamps for operation' on direct current, having one hot cathode around which the above described light phenomenon is to be produced. 1

While the second of the conditions above indicated may be easily obtained by making the lamp bulb'of adequate size and shape, the first conditionrequires special consideration in every case to make sure that. the shape and arrangement of the electrodes will fulfill the necessary require ments. The present invention covers special classes of electrode systems which readily fulfill the first mentioned condition and moreover have some advantages as regards simplicity of construction, efficiency .of light. reliable operation and so forth, the object in view in this connection being to create around the surface of the hot cathode, a condition'of the electric field as uniform as possible in order to increase the reliability and efiiciency of the light excitation.

'According to the present invention this is achieved by electrode systems in which the emissive cathode surface or its indefinitely or unlimited imagined extension or prolongation is enclosed by the anode structure.

ever, also be arranged in the neck of the lamp or at some other part of the lamp where it can interfere but little with the light emission.

The accompanying drawing illustrates by way of example various methods of carrying out the invention in practice.

Fig. 1 shows a lamp with a spiral-shaped anode, Fig. 2 a lamp with a cage-shaped anode and Fig. 3 a lamp with a ring-shaped anode arranged in the neck of the lamp.

In all the figures the lamps'have a globe or pear-shaped glass bulbl which is filled with one or more rare gases and in which the electrode system is arranged. The hot cathode is arranged in the central part of the lamp bulb l and consists of a tube 2 of nickel for example which, on its outside, is covered with a thermionic active layer emitting electrons when heated. The heating of the tube 2 iseifected by means of a heating filament 3 passing through the interior of the tube, the lower end of the heating filament being connected in Figs. 1 and 2 to the terminal 4, and in Fig. 3 to terminal 5, while its upper end is shown in Figs. 1 and 2 as being in conductive connection through the anode with the other terminal 5, and in Fig. 3 through the tube 2 with the terminal l so that a closed, metallic conductive circuit is formed. The tube 2 is closed at both ends with stoppers G, 'l of a refractory. insulating material and each of the stoppers has a central bore for the passage of the heating filament 3 into and out of the tube. The hot cathode tube 2 is provided at its lower end with a clip or clamp 2 by which it is carried on the supporting wire t. A piece of wire 9 fastened to the latter in oblique upward direction serves as a strutfor supporting the lower stopper 6 to prevent its falling out. The tube 2 also supports the heating filament 2. The heating filament can be separated from the nickel tube by an insulating body.

The heating filament may, particularly with an anode arranged as shown in Fig. 3, be formed like a loop or hairpin so that it both enters and leaves the tube 2 at'the lower end thereof. In

. that case the upper end of the tube will serve merely for holding the filament, while a conductive connection between the heating filament and the tube 2 is provided at the lower end of the latter only.

In Figs. 1 and 2 the anode encloses the hot cathode 2. In Fig. 1 it is a spiral or screw-shaped wire Ill and arranged in such a way that the hot cathode or the axis of the cylindrical tube 2 substantially coincides with the axis of the screw.

. In Fig. 2 the anode forms a cage consisting of a number of parallel wires or rods II which also lie parallel to the axis of the hot cathode and at their ends are connected with each other; by annular conductors H. The hot cathode lies in the centre of the anode cage. Any suitable numher of parallel rods ll may be provided, and in some cases two anode rods are sufficient which are arranged in the same plane as and equidistant from the hot cathode.

In Fig. 3 the anode is, differing from the examples described so far, arranged in the neck of the bulb and has the shape of an annular conductor ll enclosing the mount IS. The arrangement is such that thegeometrical axis of the hot cathode coincides with the geometrical axis of the anode ring it so that if the hot cathode tube were prolonged downward indefinitely it would be enclosed by the anode structure M. This particular construction is very simple and there are no structural parts in the interior of the lamp bulb, which might interfere with the extension of the light;

In Figs. 1 and 2 the anode is on the one hand in conductive connection with the leading-in wire 5, and on the other hand, by means of the con ductive cross bar or bridge IS with the heating filament 3, so that anode and heating filament 3 are electrically connected in series. The bridge l6 also serves for keeping the filament 3 tight. The anode is supported by the structural part II. In Fig. 3 the cross bar I8 which connects the upper filament end conductively with the tube 2 keeps the filament 3 taut.

In the foregoing only a few particularly simple examples of carrying out the invention are described and it is evident that there exist numerous other constructions falling within the scope of the invention. In particular the shape and size of the lamp bulb may be varied in many different ways provided the conditions hereinbefore defined are observed. The operating conditions and quantities (gas pressure, operation voltage, composition of the gas-filling and so forth) must in every case be 50 selected according to the nature of the gas-filling that an' 'excitation of the gas to 1uminescenoe i'spossible; if this condition is observed the selection of the operating condi-, tions is in no way limited. The gas-filling of the lamp, may be a pure rare gas mixture, or it may contain additions of other gases or vapours, mercury vapour for example. The electric field intensity should preferably be so great that the gas having the greatest atomic weight which is at the greatest distance from the hot cathode, is still excited to luminescence.

I claim:-

1. A direct current electric cathode-glow lamp, comprising a translucid bulb, a filling in said bulb consisting mainly of at least one rare gas, a metal cathode in said bulb having a coating of the alkaline earth type, a resistance type heater for said cathode, means for energizing said heater, a wire anode in said bulb consisting of an annulus symmetrically disposed with respect to the cathode and at a uniform distance from the latter, 'said bulb having a base, lead-in conductors connecting the same to the electrodes and to the heater, said anode having a small total surface area with respect to the cathode area, and being located inthat portion of the said bulbnear the lead-in conductors and beyond the end of the cathode and means for applying a po'tential difference' between the two electrodes.

2. A directcurrent electric cathode-glow lamp, comprising a translucid bulb, a filling in said bulb consisting mainly of at least one rare gas, a metal cathode in said bulb having a coating of the alkaline earth type, a resistance type heater for said cathode, means for energizing said heater,

a wire constituting the sole anode in said bulb and consisting solely of an annulus symmetrically disposed with respect to the cathode and at a and means for applying a potential difference between the two electrodes.

3. A gaseous discharge device comprising an enclosing envelope having an ionizable medium therein consisting mainly of at least one rare gas, and a plurality of spaced apart electrodes within said envelope one of which is a cathode of the indirectly heated type including means for continuously supplying heat to said cathode during the operation of the device and the other of which is bent substantially into a helix surrounding and symmetrically disposed with respect to the cathode and at a substantially uniform distance from the latter, said means being connected in series with said electrode and connected in shunt to said cathode.

4. A direct current gaseous discharge device comprising an enclosing envelope having an ionizable medium therein, a plurality of spaced apart electrodes within said envelope one of which is a cathode of the indirectly heated type including means for continuously supplying heat to said cathode during the operation of the device and the other of which is an anode which is bent substantially into a helix surrounding and symmetrically disposed with respect to the cathode and at a substantially uniform distance from the latter, said means being connected in series with ,said anode and connected in shunt to said cathode.

5. A direct current electrode cathode glow lamp, comprising a translucent bulb, a filling in said bulb consisting mainly of at least one rare gas, a metal cathode in said bulb having a coating of the alkaline earth type, a resistance type heater for said cathode, means for continuously energizing said heater, a single anode in said bulb consistlng solely of a wire symmetrically disposed with respect to the cathode and at a uniform distance from the latter, and means for applying a potential difference between the two electrodes, said heater being connected in series with said anode and connected in shunt to said cathode and said anode having a total surface area small with respect to the cathode area.

6. A gaseous discharge device comprising an enclosing envelope having an ionizable medium therein consisting mainly of at least one rare gas, an anode and a cathode spaced apart from each other within said envelope, said cathode being of the indirectly heated type including means for continuously supplying heat to said cathode during the operation of the device and the anode being bent substantially into a helix surrounding and symmetrically disposed with respect to the cathode and ata substantially uniform distance frdm the latter, one end of said anode being connected directly and in series to one end of said heat supplying means and the other end of said anode being connected directly -to a lead-in wire, and means for connecting the other end of said heat supplying means in shunt to said cathode.-

ANTON LEDERER. 

